Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 372

April 4, 200330 counties in Illinois; 29 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2003, 11:10 AM CST for 30 counties in Illinois; 29 counties in Missouri. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2003, 11:10 AM CST (17:10 UTC)
Expired
Apr 4, 2003, 12:45 PM CST
In force
95 min
Issued by
the Storm Prediction Center
All 59 counties

Bond County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Audrain County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Jefferson County, MO, Laclede County, MO, Lincoln County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 38 km from the middle of the area, began a volume at 17:10 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 5.2 hours before the alert went out and 211 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2003-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 60 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2003-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
60 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
622 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

683 
ACUS11 KWNS 041711
SWOMCD
SPC MCD 041710 
ILZ000-MOZ000-041845-

MESOSCALE DISCUSSION 0372
NWS STORM PREDICTION CENTER NORMAN OK
1110 AM CST FRI APR 04 2003

AREAS AFFECTED...CNTRL MO INTO CNTRL IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 041710Z - 041845Z

...TSTMS EXPECTED TO DEVELOP AFTER 18Z...



A SEVERE THUNDERSTORM WATCH MAY BE REQUIRED IN THE NEXT 1-2 HOURS
ACROSS PORTIONS OF CNTRL MO AND CNTRL IL FOR THE POTENTIAL FOR
LARGE HAIL AND DAMAGING WIND GUSTS.



MIDLEVEL SPEED MAX CONTINUES TO TRANSLATE NEWD INTO THE MID MS
VLY AT MIDDAY.	NEODESHA PROFILER SHOWS 5H WINDS HAVE INCREASED
TO 80 KTS AND EXIT REGION OF THIS JETLET WILL BE SPREADING ACROSS
CNTRL MO TOWARD CNTRL IL EARLY THIS AFTERNOON.	TCU FIELD HAS
INCREASED FROM SGF-JEF-VIH AS BOUNDARY LAYER CONTINUES TO
DESTABILIZE.  TEMPERATURES IN THE LOW-MID 70S AND DEW POINTS IN
THE UPPER 50S BENEATH VERY STEEP MIDLEVEL LAPSE RATES ARE
CONTRIBUTING TO MLCAPES OF 1000-1500 J/KG.  GIVEN APPROACH OF
LARGE SCALE ASCENT AND INCREASING SURFACE CONVERGENCE AHEAD OF
THE FRONT SITUATED JUST NORTH OF JLN-SEDALIA-CMI...TSTMS SHOULD
DEVELOP RAPIDLY JUST AFTER 18Z.  VERTICAL SHEAR PROFILES WILL BE
MORE THAN SUFFICIENT TO SUPPORT ORGANIZED SEVERE TSTMS. 
SUPERCELLS ARE POSSIBLE...BUT ACTIVITY SHOULD QUICKLY EVOLVE INTO
LINE SEGMENTS WITH DAMAGING WINDS AND LARGE HAIL LIKELY.  TSTMS
SHOULD MOVE NEWD NEAR/NORTH OF STL METRO AREA AND INTO CNTRL IL
LATER THIS AFTERNOON.



..RACY.. 04/04/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LOT...ILX...LSX...SGF...EAX...

39249272 39919063 40748794 40008787 39208822 38548930
37899031 37469283 38169341

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 7:23 AM CSTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 55 more97 min
Apr 4, 9:47 AM CSTMesoscale DiscussionSPCClark, Coles, Crawford, Cumberland, Douglas, Edgar and 9 more58 min
Apr 4, 12:05 PM CSTTornado WatchSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 10 more5 hr
Apr 4, 1:12 PM CSTMesoscale DiscussionSPCBond, Brown, Calhoun, Cass, Champaign, Christian and 35 more93 min
Apr 4, 1:29 PM CSTMesoscale DiscussionSPCBureau, Cook, DeKalb, DuPage, Grundy, Kane and 8 more91 min
Apr 4, 2:35 PM CSTTornado WatchSPCBond, Champaign, Christian, Clark, Clay, Clinton and 26 more5 hr
Apr 4, 3:10 PM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Coles, Cumberland and 25 more2 hr
Apr 4, 4:25 PM CSTTornado WatchSPCAlexander, Bond, Clay, Clinton, Edwards, Franklin and 24 more6 hr
Apr 4, 5:11 PM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Clinton and 24 more2 hr
Apr 3, 8:39 PM CSTMesoscale DiscussionSPCAdair, Andrew, Atchison, Buchanan, Caldwell, Carroll and 20 more2 hr
Apr 3, 9:20 PM CSTSevere Thunderstorm WatchSPCAdair, Andrew, Atchison, Buchanan, Caldwell, Clay and 17 more6 hr
Apr 3, 11:44 PM CSTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Clinton, Daviess and 13 more2 hr
Apr 4, 1:47 AM CSTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Clinton, Daviess and 12 more88 min
Apr 4, 4:43 PM CSTMesoscale DiscussionSPCDunklin, Pemiscot3 hr

Nearby

Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Missouri, 2003Every mesoscale discussion in 2003

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.